Random access data storage apparatus



Nov. 26, 1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Shet 1 Tia. l.

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Nov. 26, 1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 2 IIIIIIIII INVENTOR. WARD W. BEMAN Y Mim Attorney Nov. 26,1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 3 INVENTOR. WARD W. BEMAN A" orney Nov. 26, 1968 w. w.BEMAN RANDOM ACCESS DATA STORAGE APPARATUS l6 Sheets-Sheet 4 OriginalFiled June 24, 1957 INVENTOR. WARD W. BEMAN Attorney 7 Nov. 26, 1968 w.w. BEMAN RANDOM ACCESS DATA STORAGE APPARATUS l6 Sheets-Sheet 5.

Original Filed June 24, 1957 INVENTOR. WARD w. BEMAN Nov. 26, 1968 w. w.BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 6 INVENTOR. WARD W. BEMAN BY ray/Zun Attorney Nov. 26, 1968W. BEMAN RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24,1957 l6 Sheets-Sheet 7 T'iqleab.

Tiny 15E INVENTOR. WARD w. BEMAN Nov. 26, 1968 w W. BEMAN 3,413,528

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 8 INVENTOR. WARD W. BEMAN E] E; faf im w Attorney Nov. 26,1968 w. w. BEMAN RANDOM ACCESS DATA STORAGE APPARATUS l6 Sheets-Sheet 9Original Filed June 24, 1957 INVENTOR. WARD w. BEMAN Attorney Nov. 26,1968 w. w. BEMAN RANDOM ACCESS DATA STORAGE APPARATUS 16 Sheets-Sheet 10Original Filed June 24, 1957 VQL INVENTOR. WARD W. BEMAN BY v.3 v 3 @QL\. H Nmw Q 1 I 3 LI 5 NM N3 N5 Q m Q E V3 3%? E @E m? vb \Q Eizmsaww 02095b.

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Attorney Nov. 26, 1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 11 Tina. E E.

l l l INVENTOR. WARD W. BEMAN Attorney Nov. 26, 1968 w. W. BEMAN RANDOMACCESS DATA STORAGE APPARATUS l6 Sheets-Sheet 12 Original Filed June 24,1957 INVENTOR. WARD W. BEMAN E. ii

Attorney Nov. 26, 1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 15 'IIIlIIIIIIIl// INVENTOR. I I WARD BEMAN Attorney Nov.26, 1968 w. w. BEMAN 3,413,628

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed. June 24, 1957 16Sheets-Sheet l5 INVENTOR. WARD W. BEMAN Mix/M Nov. 26, 1968 w. w. BEMAN3,413,523

RANDOM ACCESS DATA STORAGE APPARATUS Original Filed June 24, 1957 16Sheets-Sheet 16 Attorney R m A QQN m M 2222 20222 6228 m E M 222 922 x296.226 M. M 1 2mm W 2v \nmww m A E26 222 6228 w RN 2262.6 v 62.22222.6266262 .222 v W. 6228 25.6 2622 1 222m 2 \22 5.5.252 2 2 62 EN N \N 222322282 PS 2 23: 2222.22 A w J .636 A 2222 1 2233626 A @2632 2622.22229262266 .2321 922 i E32 2 1 2226 A 1 2w 2225mm 2 2 2 6228 2.62;; v622222 2226 h m 222 226.66 226222 .2625 M E .6 29. 22322282 326 232 6228A 29622 A 2223 1 22326222 A 22632 222 232 222228266 2228 2322 922 $622 62w United States Patent 3,413,628 RANDOM ACCESS DATA STORAGE APPARATUSWard W. Benian, Glendale, Calif, assignor to Whittaker Corporation, acorporation of California Continuation of application Ser. No. 667,635,June 24,

1957. This application Sept. 26, 1967, Ser. No. 670,809 27 Claims. (Cl.340-1741) This application is a continuation of SN. 667,635 filed June24, 1957.

This invention relates to random-access data storage apparatus, andparticularly to apparatus for storing a multiplicity of record elements,such as micro-film frames, ferro-electric tapes, magnetizable wires, ormagnetizable tapes, having data recorded thereon, for selecting onerecord element or a sequence of record elements from among saidmultiplicity of record elements and for recording data on or readingdata from said selected record element or elements.

Many modern devices, such as automatic digital computers, requirefacilities for the storage of large quantities of data for an indefiniteperiod, together with means for selecting a particular segment orsegments of the stored data and reading the selected data out at anydesired time, without the necessity of hunting through the whole body ofstored data to find the desired segment. Also, should it becomenecessary to delete or add data, such alterations should be capable ofbeing made quickly and conveniently.

A particularly useful type of data storage is in the form of spooledrecords such as micro-film, magnetic wire, or magnetic tape. It iscustomary to use such spooled records in the form of substantial lengthssupported on reels and to read the data from the record by running itfrom the storage reel past a reading station and onto another reel. Suchan arrangement makes it rather difiicult to obtain quick access to anyparticular segment of data which may be stored in a random positionalong the length of the record. A substantial amount of time is requiredto hunt for and locate a particular desired data segment.

It is now proposed, in accordance with the present invention, to usesuch records in substantially shorter lengths than has been customarilydone in the prior art. For example, a record length of approximatelythree feet has been found to be satisfactory. The present inventionprovides apparatus for storing a multiplicity of such record lengths ina compact space, mechanism for selecting a particular one of themultiplicity of stored record lengths for reading or for writing, i.e.data storage, and apparatus for scanning the selected record to performthe reading or writing function as required.

An object of the present invention is to provide improved means forstoring a multiplicity of short lengths of records.

Another object of the invention is to provide improved means forselecting a particular one of a multiplicity of stored records.

Another object is to provide an improved means for scanning the selectedrecord by effecting a relative motion between the reading or writingstation and the record.

Another object is to provide an improved means for guiding the relativemovement between the reading or writing station and a length of therecord.

The foregoing objects of the invention are attained in the apparatusdisclosed herein, by storing the records in a plurality of rows orcolumns.

In its simplest form, the invention comprises a multiplicity of elongaterecord elements placed side by side in a two-dimensional array. In theoperation of the mechanism, the storage position of the segment soughtis ice defined by Cartesian coordinates. The elongate record elementsare disposed upon the surface of the two-dimensional plane defined bythese coordinates. The position or location of any given record segmentis related to accurately fixed divisions on the X and Y coordinates ofthe plane. In this simple embodiment of the data storage device, therecords may be considered to lie upon a planar surface coated with arecording material having defined rows or columns thereon for addressingthe recorded segments. A data address fed to the storage apparatus woulddirect the reading and writing search head to a particular XY coordinatewhereupon it would scan the surface along one of the two coordinates,for a distance corresponding to one word length. As the search headscans, it continues to maintain a record of its position; butsimultaneously it is detecting data signals derived from the surface,said signals having been previously written upon the surface from awrite command. Used in this manner, a storage device having a workingsurface of approximately 1200 square inches could store 20,000 36- digitbinary words, based upon a signal packing density of one unit per squaremillimeter. This density is readily achieved by conventional magneticrecording techniques. For many applications this might be an entirelysutficient amount of storage. However, if an even greater capacity isrequired further modification can be employed whereby true volumetricstorage is achieved. A data address may consist of not only the XYcoordinates of a two-dimensional plane, but a Z coordinate as Well. Thereading and writing head might then position itself over the XY addressas directed by a command from the controlling computer. Located directlybeneath each possible XY address would be an elongate record element,such as a magnetizable wire, filament or tape, which is withdrawn fromthe surrounding similar filamentary elements, the direction ofwithdrawal being essentially perpendicular to the XY plane in the Zcoordinate. As the filamentary record element is withdrawn, it passes amagnetic read station which detects the magnetized pulses existing alongthe length of the filament. The Z coordinate part of the overall addresswould determine at which point along the filament read would commence,and the reading operation would continue for one word length. After theword is read out into an auxiliary storage, the filament would bereturned to its original location, and the search head would beavailable for the next command. In such a device, tape records may bestored in a plurality of cells. Each cell holds a purality of records,for example, of

the order of 200. The records are frictionally retained in the cell inclosely packed relation. Means are provided for permitting the partialwithdrawal of a particular record, and simultaneously preventing theadjacent records from being drawn along with the removed records by thefriction between their surfaces; improved grip tabs are also provided atthe ends of the records so that they may be selectively seized andpartially pulled out of the stack of records in the cell.

In another embodiment, magnetizable wires of short length are arrangedin rows and a single wire is removed from any selected position in anyselected row by a suction head moved into position adjacent the end ofthe single wire. The suction head can be provided with extendable meanswhich moves over the end of the single wire after the head has beenpositioned in order to increase the effectiveness of the suction on thesingle wire and to isolate the effect of suction on adjacent wires. In athird embodiment of the invention, a two dimensional surface is coveredby a magnetizable material on which data can be recorded or read bymovement of a magnetic head over the surface.

Other objects and advantages of the invention will become apparent froma consideration of the following specification and claims, takentogether with the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of a single cell of tapes showing the end of thecell from which the tapes are withdrawn;

FIGURE 2 is a fragmentary, cross-sectional view taken on the line 11-11of FIGURE 1, showing the construction of the tape cell;

FIGURE 3 is an enlarged perspective view of a group of the tapes in thecell of FIGURES 1 to 2, showing the tab end structures by which thetapes may be seized;

FIGURE 4 is a view similar to FIGURE 3, showing a modified form of tabend structure;

FIGURE 5 is a cross-sectional view through a tape cell, showing one formof mechanism for frictionally holding the sides of the tapes;

FIGURE 6 is a plan view, similar to FIGURE 1, on an enlarged scale,showing a modified form of tape storage cell, with certain of the tapesand parts removed;

FIGURE 7 is a cross-sectional view of the opposite end of a tape cellfrom that shown in FIGURE 2, showing mechanism to prevent thesimultaneous withdrawal of the two adjoining tapes to the one selected;

FIGURE 8 is a cross-sectional view taken on the line VIIIVIII of FIGURE7;

FIGURE 9 is an exploded perspective View, showing a tape drive plate andthe principal parts of the mechanism for seizing and withdrawing a tapefrom the cell of FIGURE 1;

FIGURES 9A and 9B are diagrammatic illustrations of the operation of atape reversing mechanism included in FIGURE 9;

FIGURE 10 is a perspective view showing a selection plate assembled withthe tape drive plate of FIGURE 9;

FIGURE 11 is an elevational view, with certain parts broken away andothers shown in section, illustrating the tape driving and readingmechanism on the tape drive plate of FIGURE 9;

FIGURE 12 is a fragmentary view similar to a portion of FIGURE 11,showing a modified form of tape reading head and guide means;

FIGURE 13 is a cross-sectional view through a tape magazine forming apart of the tape reading mechanism of FIGURES 9 and 10;

FIGURE 14 is an elevational view of the tape seizing and drivingmechanism of FIGURES 9 and 10, with certain parts broken away forpurpose of clarification;

FIGURE 15 is an enlarged plan view of the top of a tape cell, showingthe relationship of the pincer jaws to the tapes in the cell;

FIGURE 16 is an enlarged fragmentary elevational view taken on the lineXVIXVI of FIGURE 15, looking in the direction of the arrows;

FIGURE 17 is a fragmentary perspective view showing the search headincluding the tape gripping and driv ing means, and means forpositioning the search head with respect to a storage cell;

FIGURES 18A, 18B, 18C, 18D and 18B, illustrate schematically fivesequential positions of the tape seizing and driving mechanism ofFIGURES 9 to 11;

FIGURE 19 is an electrical wiring diagram showing a control system forthe tape gripping and driving mechanism;

- FIGURE 20 is a wiring diagram of mechanism for manually selecting aparticular tape to be gripped by the tape gripping mechanism, togetherwith apparatus for automatically selecting the tapes in a predeterminedsequence;

FIGURE 21 is a wiring diagram of additional mechanism for automaticallyselecting the tapes in a predetermined sequence;

FIGURE 22 is.a plan view of a complete storage unit including aplurality of tape cells, a carriage supporting a search head, and coarsepositioning mechanism for positioning the search head adjacent any cellamong the plurality of cells in the complete unit;

FIGURE 23 is a fragmentary plan view similar to FIGURE 22, but on anenlarged scale, and with the search head cover removed, and showingdetails of the carriage and search head construction;

FIGURE 24 is a view partly in section along the line XXIVXXIV of FIGURE23 and partly in elevation; showing a detail of the coarse positioningmechanism;

FIGURE 25 is a wiring diagram of a circuit for the coarse positioningmechanism of FIGURES 22 and 23;

FIGURE 26 is a perspective view of a three-dimensional data storageapparatus showing the storage bins for supporting the filamentary recordelements and the search head for selecting and partially withdrawing agiven record element;

FIGURE 27 is an enlarged fragmentary, top plan view of a group ofmagnetizable wires showing the cell spacers and dividers and a certainselected wire;

FIGURE 28 is a fragmentary cross sectional view showing a modified formof the wire withdrawing mechanism of FIGURE 29;

FIGURE 29 is an enlarged exploded perspective view of the search head ofFIGURE 25 suitable for use with magnetizable wire and having certainparts shown in phantom or broken away to show the mounting and drivingmechanisms;

FIGURE 30 is a block diagram of the three-dimensional storage apparatusof FIGURE 1;

FIGURE 31 is a perspective View of a two-dimensional search head withcertain parts shown in phantom or broken away to show the drivingmechanism;

FIGURE 32 is an elevational view of the two-dimensional read-write headof FIGURE 30 with the case shown in section;

FIGURE 33 is a block diagram of the two-dimensional data storageapparatus of FIGURE 4.

FIGURES 1 t0 3-Tape storage cell The first embodiment of the inventionto be described stores recordable tapes in a plurality of cells. Eachcell holds a plurality of tapes, for example, of the order of 200. Thereis shown in FIGURES 1 and 2 a tape storage cell generally indicated bythe reference numeral 1 and comprising a frame member 2 on one side of aplurality of tapes 5. On the other side of the tapes is another framemember 3. The frame member 2 is generally channelshaped throughout mostof its length, but is provided near the illustrated end of the tapeswith a projecting tongue 2a, which divides the tapes into two groupsnear that end of the cell. In the structure illustrated, the tapes areselected from the upper end of the cell. While that orientation of thecell is preferred, it may be readily seen that the cell may be invertedand the tape withdrawn from the lower end, or that the cell might haveany other angular orientation.

The frame member 3 is illustrated as simply a fiat plate. The framemembers 2 and 3 may be fastened together by any suitable means, forexample, by welding.

The tongue 2a separates the tapes in the cell 1 into two groups, andholds the upper ends of the tapes closely packed against each other, sothat their adjacent surfaces are in frictional engagement. The remainderof the lengths of the tapes are held relatively loosely by the framemembers 2 and 3, as illustrated in the lower portion of FIGURE 2.

If desired, a suitable dry lubricant may be applied to the tapesurfaces. Molybdenum sulfide has been found to be very satisfactory.

As best seen in FIGURE 3, the upper ends ofthe tapes are cut away bymeans of diagonal cuts at the opposite corners, so that each tapeterminates in a peak or tab 5a. The tapes 5 are arranged in groups inthe cell, each group having a convenient number of tapes and beingtermed hereinafter a column of tapes. FIGURE 3 .is an enlarged view ofthe tape selecting end of one column of tapes. In any column of tapes,the respective tapes in the column have their tabs appearing at equallyspaced distances across the width of the tape. This spacing of the tapes5a facilitates the selection and seizing of the tapes for purposes ofwithdrawing them from the cell.

FIGURE 4 FIGURE 4 illustrates a modified form of structure for the tabends of the tape. This figure illustrates two columns of tapes 6 havingtheir upper ends cut away so as to form square end tabs 6a, equallyspaced across the width of a column.

FIGURE 5 This figure illustrates a mechanism for frictionally holdingthe sides of the tape in a cell to prevent accidental removal. A portionof the frame member 3 is cut away as illustrated at 3a to provide anOpening to receive a pad 7 held frictionally in place against the sidesof the tapes 5 by means of a lever arm 8 biased toward the pad 7 by aspring 9. This arrangement prevents a tape which is not seized at itsupper end from following an adjacent tape when that adjacent tape isseized.

FIGURE 6 This figure illustrates an alternative method of stacking tapesfor preventing the tapes on either side of a selected tape fromfollowing it when the selected tape is seized and pulled. In thisarrangement, each tape 5 is separated from its neighbors by a spacer 10.The ends of the spacers are of double thickness, as shown at 10a, sothat each tape lies between two spacers. The spacers are fixed to theframe members 2 and 3 by means of rods 11 which extend through suitableapertures in the spacers and are attached to the frame member bysuitable means, for example, screws 12.

FIGURES 7 and 8 These figures illustrate a preferred form of machanismfor holding adjacent tapes against movement with a selected tape. Thisparticular mechanism is referred to hereinafter as the odd-evenmechanism. In this arrangement, the lower ends of the tape are cut awaywith a smooth out on one side, as illustrated at 5b, and a deeplynotched cut on the opposite side, as illustrated at 50. The smooth cuts5b have the same depth throughout their length as the bottoms of thenotches 5c. The adjacent tapes are located with their notched cuts onopposite sides.

Located on opposite sides of the frame members 2 and 3 are a pair oflevers 13 and 14 having at their ends rollers 15 adapted to engage thebottoms of the notches 5c. The levers 13 and 14 are pivoted at 16 to thebottom of the frame member 2. A screw 17 is threaded into the lower endof the lever 14 and has a shank 17a projecting through the lower end oflever 13. A spring 18 is held in compression between the lower end oflever 13 and a flange 17b on the screw 17. Spring 18 is effective tohold the rollers 15 yieldably in engagement with the bottoms of thenotches 50.

When a particular tape 5 is withdrawn upwardly from the stack of tapesin the cell, then its notched edge 50 cams its associated roller 15 andits supporting lever outwardly. The adjacent tapes on both fiat sides ofthe moving tape are held against vertical movement by the engagement ofthe opposite roller 15 with their notches 50. Note that the roller 15engages the notches 50 on the adjacent tapes within the deep, smooth cuton the moving tape and so is not forced outwardly by the camming action,but remains in engagement with the notches 5c and is effective to holdthose adjacent tapes against vertical movement.

FIG URES 9 t0 1 8Search head These figures illustrate the details ofconstruction of the search head 19, which includes the mechanism bywhich a particular tape within a cell is selected, seized, Withdrawnfrom the cell, driven past a reading or writing head, and restored toits position of storage within the cell.

The principal parts of the search head are mounted on two parallelplates, hereinafter referred to as the selection plates 19a and the tapedrive plate 1% (see FIGURE 10). The two plates 19a and 1% are heldtogether in spaced relationship by any suitable means, for example,braces 21, as seen in FIGURE 10.

The selection plate 19a supports a pair of pineers generally indicatedby the reference numeral 22, and including a pincer jaw 23 and aselector jaw 24. The pincer jaw 23 and the selector jaw 24 are locatedbetween the plates 19a and 1%. The pincer jaw 23 is fixed on a rockershaft 25, which is journaled in plate 19a. Outside the plate 19a, thereis fixed on the rocker shaft 25 a lever arm 26. The other end of arm 26,as best seen in FIGURE 15, is connected by a spring 28 to an armatureoperated by an electromagnet 27. Another spring 29 is connected betweenarm 26 and a bracket fixed on plate 19a. Spring 29 acts in opposition tospring 28, both springs being stressed in tension. The spring 29 isconsiderably weaker (i.e., it has a lower spring rate) than the spring28, so that when electromagnet 27 is energized, the arm 26 is movedupwardly against the bias of the light spring 29, thereby rotating therock shaft 25 and rnoving the pincer jaw 23 into engagement with theselector jaw 24. After the jaws engage, further upward movement of thearmature and the electromagnet stretches the spring 28, and loads theend of the lever 26 heavily, forcing the jaws tightly together. The jawsare thus brought into initial engagement without substantial impact, andare thereafter loaded more heavily so that they engage one anothertightly.

The face of the pincer jaw 23 which engages the selector jaw 24 is aplane surface. The opposing face of selector jaw 24 has a raised nub 30(see FIG. 16). The lower end of the nub 31) is pointed, as shown at311a. The selector jaw 24 is fixed on a rod 31 which is mounted in theselection plate 19a for sliding movement with respect thereto. Thissliding movement is controlled as required to bring the nub 3tselectively into alignment with any one of the pointed tips 5a of thetapes 5 stored in the cell above which the search head 19 is located.

Outside the plate 19a, the rod 31 is provided with a flange 31a. Aspring 32 is held in compression between the flange 31a and the plate19a and biases the rod 31a and jaw 24 for movement toward plate 19a. Theouter end of rod 31 engages a stepped cam 33 fixed on a shaft 34 whichis rotated by means of a suitable stepping mechanism 35. The step-pingmechanism 35 is shown in external elevation in FIGURES 10 and 14. Anysuitable internal structure of the stepping mechanism may be use-d, oneparticular conventional form of stepping mechanism being illustrateddiagrammatically in FIGURE 20. The shaft 34 is journaled in a block 36fixed on the outside of plate and projecting therefrom. It will bereadily understood, particularly with reference to FIGURES 15 and 16,that when the search head is in any fixed position above a cell 1, aparticular column of the tapes in the cell is located between the pincerjaws 23 and 24. By shifting the pincer jaw 24 laterally of the cell, thenub 30 may be brought into alignment with any one of the tapes in theparticular column. The cam 33 performs the function of shifting theselector jaw 24 and the energization of the selecting mechanism 35determines the alignment of the nub 30 with a particular tape end.Thereafter, the pincer jaw 23 is moved toward the selector jaw 24, asdescribed in detail below, so that the end of the selected tape isseized between the plane surface of the jaw 23 and the nub 30.

The search head 19, including the plates 19a and 19b, is journaled on ashaft 37 which is fixed in a carriage 20, (see FIG. 23) on which ismounted a bracket 33. Fixed on the bracket 38 is an electromagnet 39,whose armature is connected through a link to the end of an armprojecting from the plate 19. The armature and link 40 are biased by asuitable spring so that when the electromagnet 39 is 'deenergized, theentire search head assumes an upwardly tilted position, as shown forexample in FIGURE 18A. When electromagnet 39 is energized, the link 40is drawn upwardly and the search head is lowered to the horizontalposition shown in FIGURES 14 and 188. Note that when the search head isin its normal position, the pincer jaws Z3 and 24 are lifted upwardlyand clear the tops of all the tapes 5, so that the search head may thenbe moved endwise of the cell to select a particular column thereof. Thecolumn selecting mechanism is illustrated in FIGURES l7 and 23, andincludes a stepped cam 41 shown as acting on a follower 20a attached tothe carriage 20 and effective to position the carriage longitudinally ofthe cell, i.e. from left to right or right to left as viewed in FIGURES14 and 23. A spring 2% biases the carriage 20 so as to hold follower 20ain engagement with cam 41. The stepped cam 41 is mounted on a shaft 42and is positioned by a stepping mechanism 43, which may he similar instructure to the stepping mechanism 35. The stepping mechanism 43 andthe stepped cam 41 move the entire search head carriage 20, and aremounted on a gross positioning carriage 44, shown and described ingreater detail below in connection with FIGURE 23.

A pair of tape drive rollers 45 and 46 (see FIGURE 9) are respectivelyfixed on shafts 47 and 48 journaled in the plate 1% and driven by areversible drive mechanism mounted on the back of plate 191). The shafts47 and 48 carry, on the back of plate 1%, a pair of rollers 49 and 50,respectively, which continuously engage each other, so that the shafts47 and 48 always turn in opposite directions. One or the other of therollers 49 and 50 is driven through a shiftable idler roller 51 by aflywheel 52, which is rotated by a motor 53. Motor 53 also drives,through a clutch 54, a timing cam 55 which actuates a cam follower 56connected to a switch 57, which may be a micro-switch. There is alsoprovided a cam detent solenoid 58, which operates a detent 59 biased bya spring 60 to engage a notch 55a in the periphery of the cam 55. Thecam 55 cannot rotate until the solenoid 58 is energized to release thedetent 59 from the notch 55a. Detent 59 fixes the starting position ofcam 55, so that its operation is accurately timed.

The direction of rotating of the shafts 47 and 48 is determined by areversing mechanism best shown diagrammatically in FIGURES 9A and 9B. Itmay there be seen that the idler roller 51 is journaled on the end of anarm 61, whose opposite end is rotatable about the axis of flywheel 52.The outer end of arm 61 is shiftable by means of an electromagnet 62between the position shown in FIGURE 9A, wherein the idler roller 51lies between the flywheel 52 and the roller 49, and the position ofFIGURE 9B in which the idler roller 51 lies between flywheel 52 anddrive roller 50. A spring 63 biases the arm 61 to the position of FIGURE9A. When the parts are in that position, the tape drive rollers 49 and50 rotate in a direction to drive downwardly a tape passing betweenthem. When the solenoid 62 is energized, the parts move to the positionof FIGURE 9B, whereupon the tape drive rollers 49 and 50 becomeeffective to drive upwardly a tape passing between them.

Above the tape drive rollers 45 and 46, the plate 1% carries a read orwrite head 64, and pressure pad means 65 (see FIG. 11) for holding amoving tape in cooperative engagement with the read or write head 64.Above the read or write head 64 is located a magazine 66, for receivingand coiling a tape as it moves upwardly past the read head 64.

Throughout this specification, the head 64 is spoken of at times as aread head. It is well understood by those skilled in the art that thehead 64 may alternatively function as a write head on any given movementof the tape past it. In other words, it may translate data either to orfrom the tape. It is spoken of as a read head in the present descriptiononly for the purpose of simplifying the specification.

The magazine 66, as best seen in FIGURE 13, comprises a cylinder havinga lateral opening 66a for receiving a tape 5. A leaf spring 67 preformedwith a sinous contour is fixed at one end to the inner wall of thecylinder, so that it provides a yieldable cushion against which the tape5 is driven as it moves upwardly into the magazine, By virtue of thespring 67, the effective inner diameter of the magazine casing expandsas the succeeding turns of tape are driven upwardly into the magazine66, so that the coil of tape rotates, sliding over the high points ofthe flat spring 67, and there is no frictional slipping between theturns of tape as it piles u in the magazine. The amplitude of the sinouscontour of the spring 67 is made sufiicient so there is ample roomwithin the magazine 66 to receive an entire tape length 5.

As is well known in the art, each tape 5 may carry several parallelchannels which are read or written simultaneously. Each channel requiresa separate reading or writing coil. In the head 64 there may be a row ofupper reading or writing units 64a, which engage alternate channels onthe tape, and a row of lower reading or writing units 641), which engagethe other channels on the tape.

A preferred form of pressure pad mechanism for holding the tape inengagement with the read head 64 is illustrated in FIGURE 11. Thismechanism includes a frame 68 on which are journaled a pair of rollers69 and 70, respectively adapted to engage the side of the tape oppositethe upper and lower reading units 64a and 64b. The frame 68 is pivotedon a rod 70 slidably mounted between guides 71, and biased by a spring72 to hold the rollers 69 and 70 in contact with the tape.

It has been found that the pressure pad 65 cooperates effectively withthe magazine 66 and with the tape cell 1 to maintain a tape being readin accurate alignment with the read head 64, and that this alignment ismaintained during both upward and downward movements of the tape, sothat a tape may be read during an upward movement and written during thefollowing downward movement, or vice versa.

An alternate pressure pad arrangement is shown in FIGURE 12. In thisarrangement, the pressure pad is generally indicated at 73, and includesa pad 74 of sponge rubber or similar resilient material mounted on aframe 75 which is positioned by an electromagnet 76. A spring (notshown) biases the frame 75 to a position wherein the pad 74 is free ofthe tape 5. When it is desired to read or write the tape, theelectromagnet 76 is energized, and holds the pad 74 firmly against theopposite side of tape 5, thereby maintaining it in smooth operativecontact with the read head 64. If desired, the face of the pad 74 may beprovided with a flexible metal coating.

Operation of search lzeadFIGURES 18A to 18E A tape is selected by movingthe search head to bring it into alignment with a particular column oftapes and by moving the selector jaw 24, to bring the nub 30 intoalignment with a particular tape. During the tape selection, the searchhead is tilted as shown in FIGURE 18A. These two positioning operationsare accomplished by sequential energization of the stepping mechanisms35 and 43, as described in detail below. After the tape selection iscon1- pleted, the search head is then moved through a tape seizing andreading cycle illustrated in FIGURES 18A to 18E.

First the electromagnet 39 is energized to tilt the search head to thehorizontal position shown in FIGURE 188, after which the electromagnet27 is encrgized to move pincer jaw 24 toward engagement with selectorjaw 25, thereby seizing the particular tape 5 with which the nub 30 onthe selector jaw 24 has been aligned. The electromagnet 39 is thendeenergized, and the search head tilts

1. DATA STORAGE APPARATUS, COMPRISING: A PLURALITY OF ELONGATED RECORDS,MEANS FOR MOUNTING SAID RECORDS IN A MATRIX HAVING X AND Y AXES WITHEACH RECORD HAVING AN X AND Y COORDINATE ADDRESS, SAID RECORDS BEINGMOUNTED SUBSTANTIALLY PARALLEL TO EACH OTHER, TRANSDUCER MEANS FORRECORDING OR READING DATA WITH RESPECT TO SAID RECORDS, FIRSTPOSITIONING MEANS FOR MOVING SAID TRANSDUCER MEANS WITH RESPECT TO SAIDX AXIS, SECOND POSITIONING MEANS FOR MOVING SAID TRANSDUCER MEANS WITHRESPECT TO SAID Y AXIS, MEANS OPERABLE WHEN SAID TRANSDUCER MEANS IS INAN OPERABLE RELATIONSHIP WITH A PRESELECTED RECORD FOR WITHDRAWING ONLYSAID PRESELECTED RECORD FROM SAID PLURALITY OR RECORDS IN A DIRECTIONGENERALLY TRANSVERSE TO SAID X AND Y AXES, SAID WITHDRAWING MEANSINCLUDING VACUUM MEANS FOR APPLYING A FORCE TO SAID PRESELECTED RECORD,AND MEANS OPERABLE WHILE SAID PRESELECTED RECORD IS BEING WITHDRAWN FORMOVING AT LEAST A PORTION OF SAID PRESELECTED RECORD PAST SAIDTRANSDUCER MEANS.